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Hand-Made Vacuum Tubes
djmoore writes "Over at Make Magazine, watch this video of a French amateur radio operator making and testing his own vacuum tubes. It looks like he built much of his own equipment as well. The Make poster notes: 'I love the ease with which he performs these rather high-end skills (like glass forming), the gestural flourishes (like it's hand magic), and the Zelig-esque soundtrack.'"
Yeah, like Pierre Scerri, who spent 15 years making a scale model of a Ferrari 312. Not only did he make the body, he learned to make glass in order to create the headlights, and learned to make rubber to make his own tires. It's almost unbelievable.
The theory of relativity doesn't work right in Arkansas.
Not Million Electron Volts, but
"Male Enhancer Volume System Product"
How much juice/oomph can YOUR tubes deliver?
Previously: "Linux... Toward the Sunrise..." Now: "Linux... Toward the-- No, now, part of Every Sunrise"
I can respect having an obsessive hobby. Especially when it produces such spectacular results.
However, if you're going to spend that much time, why not build a full size vehicle so you can actually drive it?
The only thing that would make this cooler is if he made his own Nixie tubes!
I thought there were issues not addressed clearly in the video. First, I thought I learned in college chemistry (now rummaging in decades-old longterm storage media) that one of the big problems was getting a good seal of glass around metal, which wasn't solved until they put together the right glass with the right metal.
Also, aren't the electrodes in a vacuum tube coated with something to prevent early breakdown? And isn't there some chemical you have to put inside the tube to absorb the gas given off when electrons smash into the electrodes? So while this is incredibly neat-looking, I don't think the tubes would last very long...
--Rob
Towards the Singularity.
It will also serve to bring us back after the collapse of society and technology.
Id like to see you make semiconductor based transistors in your basement.
---- Booth was a patriot ----
'I can respect having an obsessive hobby. Especially when it produces such spectacular results.'
Though with some people, this sort of thing can get just a bit _too_ obsessive:
http://www.sandia.gov/LabNews/LN02-13-98/cherry_story.html
'The switch mechanisms Kaczynski used were hand-made switches that he would spend weeks building...He machined his own screws.'
If you wanted to build some part of an embedded device that absolutely had to take some really ugly conditions, you could do a whole lot worse than to build that specific module using valves. Let's say you wanted to build a new module for the IIS, for example. The internal circuits can largely be protected, so conventional radiation-proof chips would be fine. However, if you wanted reliable computing elements that could be strapped to the outside of the pod, you've harsh conditions indeed. Lead-smothered rad-hardened silicon chips that can handle space tolerances and have their own heating elements would probably work. Lots of things that can go wrong, though. Complexity-wise and weight-wise you're probably not significantly better off than using thermionic valves with none of the extras.
Where else could valves be used? Easy. If the cathode and anode are deliberately mis-aligned, then one or more grids must be set to a value such that the directed power completes the circuit. If something goes wrong (too much power, something fails, whatever), then the beam is either not pushed at all or pushed far too far. In either case, you've an all-electronic circuit-breaker - ideal if you want to get rid of fuseboxes and mechanical trip-switches.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
My grandmother in Massachusetts tells stories about working in a vacuum tube factory during World War II (Raytheon maybe?). At the time, vacuum tubes did require some manual assembly. The process was not fully automated.
The last time (about 10 years ago) I had to take a big radio frequency amplifier apart (1 kW continuous wave, 2 kW in pulsed mode, so not really hobbyist stuff but in a physics lab, too expensive for all but the very wealthy hobbyists) it had lots of vaccum tubes inside and I don't think that has changed too much since then, the next one we bought (for higher RF powers) also had tubes... Admittedly, it weren't those nice looking (low power) ones with glass covers but in ceramic casings (but then the voltages required also were a bit higher, some kV were needed - and, yes, I accidentally touched something in there with a screw driver - it flew somehwere in the lab and we never found it;-).
ah ha! you are so right!, i have my nose in the HF too much, i mostly ignore VHF/UHF except when programming a police scanner...
i have a nice R.L. Drake shortwave receiver and love to listen to HF a lot, so when ham radio is the topic the HF bands are what i automatically think of...
Politics is Treachery, Religion is Brainwashing
Or... use GNASH. Plays that video fine (n.b. you might have to use the latest version, not version in Debian/stable).
He was superheating the entire structure to drive out occluded gases from the metal components. During this operation, the entire tube was surrounded by a coil driven by an induction heater, which was heating the plate and grid red hot, as well. All this takes place while the tube is attached to the vacuum pump, prior to sealoff.
I am not sure what material he was using for his filament wire, but if it was thoriated tungsten, then the "hot shot" cycle also serves to build up a surface layer of thorium oxide on the filament, and reduce it to metallic thorium. Thorium has a much lower work function than pure tungsten, and will emit electrons efficiently at a much lower operating temperature.
Yes, I am a tube geek...:) Years ago, I made a much cruder triode in a peanut butter jar as a HS physics project.
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"refining" a tube typically meant heating it up in an inductive system to burn out impurities and gas in the tube elements, and filaments may or may not also be heated up at that time. typically were. getters are often "flashed" with a high voltage impressed on them during this period to be sure the impurities are fully absorbed and can't get back into the tube metals and glass spacers.
many getters at the period in which that tube type he's duplicating used phosphorus. not as efficient as aluminum and barium, but easier to flash over. WWI, remember, you couldn't pull much vacuum. the getter had to do the job. so old tubes had funny colors inside from the getter flashover.
if this is supposed to be a new economy, how come they still want my old fashioned money?
Scientific American Amateur Scientist column
Transistors. how to make thin film,
1970 Jun, pg 141
, as sophisticated robotics didn't yet exist. The most sophisticated part of tube making, the assembly of the internal components or "mount" was done largely by hand, usually by rows and rows of women (smaller fingers) hunched over microscopes in dust-free rooms.
Once the mounts were assembled and welded onto the stems, the sealing into bulb and pumping down was somewhat automated. Done on a machine called a "sealex", the mounts would be inserted into bulbs, sealed in place, evacuated, heated to activate the cathodes, sealed off, and getters flashed, with each operation taking place at a different "station" on the sealex.
An interesting photo essay on the construction of the famous 300B audio triode is available here:
http://www.westernelectric.com/history/tour01.html
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i was kidding. and i forgot to type 'hand-made $500 volume knob"
:(
i should have clicked preview
I know that tubes give a different sound. I used to work in a small recording studio, (well, specializing in making demo tapes, rather than professional recordings) One of the bass amps (can't remember brand/model, sorry) had a switch for either solid state or vacuum tube distortion (and it's no simulation or filter, there are real vacuum tubes in there)
A lot of analogue gear gives much better distortion than any new solid state stuff. a lot of old people find that digital clipping sounds terrible. (while I like it)
When i'm recording drums, I often put the mics just a little too close, record things just a little too hot, and record to tape. I move the analogue recording to my hard drive later. It makes them sound so much bigger/fuller.
With guitar, i find i could get away with recording clean electric guitar, then throw on some VST filters later to make it sound just like an effects pedal, but if they wanted that warm tube sound, no filter came close enough, I had to actually use real, physical gear.
vintage vacuum tubes are so hard to fund when they burn out, who would have though a DIY approach would be a viable option. cool!
-I only code in BASIC.-